Lear, cast out by his daughters Goneril and Regan, rages against the storm on the heath. His fury at the elements mirrors his fury at his daughters' ingratitude, as he descends toward madness.
Lear has been turned out into a storm on the heath after Goneril and Regan have stripped him of his hundred knights and refused him shelter at Gloucester's castle. Kent (in disguise as Caius) and the Fool are with him — the Fool tries to coax him toward shelter through the entire scene, and Kent enters partway through searching for him. The storm is real to the audience (Shakespeare's stage used cannonballs rolled on metal sheets) and possibly real to Lear, although a substantial part of the speech treats the storm as a moral antagonist Lear is challenging to do its worst. This is the centre of the play's storm sequence and the moment Lear's authority passes definitively from political command to metaphysical complaint.
Lear wants the elements to finish the work his daughters have started. He is challenging the cosmos to acknowledge his suffering by destroying the world, which would at least confirm that his pain is universe-scaled rather than the embarrassing private misfortune of a stupid old king. What he wants from the storm specifically is recognition. The speech moves from commanding the elements ("Blow, winds, and crack your cheeks") to acknowledging that they owe him nothing ("I tax not you, you elements, with unkindness") to the bitter recognition that they are conspiring with his daughters. Psychologically he is in the early stages of the breakdown that will become full madness over the next two scenes. The grandeur of the rhetoric is itself a symptom — he is still trying to be a king while the role no longer exists.
The single biggest pitfall is matching your volume to the imagined storm. If you try to out-shout the weather you will be hoarse by line ten and unintelligible by line twenty. Modern productions usually quiet the storm under the speech precisely because of this. Find variations of intensity within the speech. The opening commands are vocally explosive but the middle section ("I tax not you, you elements, with unkindness") is a different register — almost reasonable, an old man trying to be fair-minded with the weather. Then the recognition that the storm sides with his daughters takes him into a new fury. Mark these movements. The Fool is on stage and is your scene partner whenever you are not addressing the sky; he is terrified and cold and Lear barely notices him, which is itself the tragedy. Verse is muscular and aurally dense — the consonant clusters in "cataracts and hurricanoes" are physical work; let them be. Don't telegraph the coming madness; this Lear is still arguing, still rational in his terms. Tempo: bursts of speed broken by sudden slownesses where the argument shifts. Breathing: this speech will expose any actor who has not done breath work.
Almost always a bad audition choice and almost always chosen anyway by ambitious actors. The problems: it requires you to invent a storm in an empty room, it tempts you to shout, it is associated with actors thirty years older than most auditioners, and the panel has heard it many times performed badly. If you do use it, you are betting that you can solve all those problems in two minutes. Best deployed for showcase contexts where you have warned the panel, for senior actor auditions, or for advanced training programs where the panel specifically wants to see you wrestle with the canon. Shows ambition, breath, verse stamina, and large-scale emotional commitment. Younger actors should generally choose something else; the speech will work against you by reminding the panel of every older Lear they have seen. If you do it, cut to the first eighteen lines and trust the architecture.
Blow, winds, and crack your cheeks! rage! blow!
You cataracts and hurricanoes, spout
Till you have drench'd our steeples, drown'd the cocks!
You sulphurous and thought-executing fires,
Vaunt-couriers to oak-cleaving thunderbolts,
Singe my white head! And thou, all-shaking thunder,
Smite flat the thick rotundity o' the world!
Crack nature's moulds, an germens spill at once,
That make ingrateful man!
Rumble thy bellyful! Spit, fire! spout, rain!
Nor rain, wind, thunder, fire, are my daughters:
I tax not you, you elements, with unkindness;
I never gave you kingdom, call'd you children,
You owe me no subscription: then let fall
Your horrible pleasure: here I stand, your slave,
A poor, infirm, weak, and despised old man:
But yet I call you servile ministers,
That have with two pernicious daughters join'd
Your high engender'd battles 'gainst a head
So old and white as this. O! O! 'tis foul!